Non-leaking fountain pen



July 26, 1955 B. F. MIESSNER NoN-LEAKING FOUNTAIN PEN Filed Jan. l5, 1952 nited States Patent O NON-LEAKING FOUNTAIN PEN Benjamin F. Miessner, Morristown, N. J. Application January 15, 1952, Serial No. 266,474

8 Claims. (Cl. 1Z0-50) This invention relates to a new and improved construction of a fountain pen and has for one of its objects a construction wherein the pen will not flood by changes in temperature and atmospheric pressure. A further object is to obtain a non-flooding pen that is easy to make and assemble, there being no interior moving parts to get out of order.

Other objects will be understood from a reading of the specification taken with the annexed drawing in which,

Figure 1 is an enlarged longitudinal view through the Pen;

Figure 2 is a section on the line 2-2 of Figure l;

Figure 3 is a view on the line 3-3 of Figure l and Figure 4 is a View on the line 4-4 of Figure 1 but including a slight addition thereto.

In the drawing, 1 is a hood which may have an inner cylindrically shaped end 2 which provides a space 3 that increases the size of ink chamber 4, that is within the barrel 5, the inner end 6 of which is press-ftted over the end 2 and beyond onto a reduced diameter of the hood 1, preferably using a silicon grease lubricant and sealing agent to make a secure and inktight joint. The barrel 5, forming the ink reservoir, is preferably made of an elastic transparent plastic material such as, cellulose nitrate of about .010 to .020 wall thickness and is longitudinally stili but transversely squeezable for the purposes which will later appear.

The hood 1 has ve bores of different diameters. The bore a, is about .01" to .015 larger in diameter than the outside diameter of the shank 7 of the pen P. The bore b is slightly smaller than the outside diameter of the pen shank 7 which is split on one side as shown to accommodate itself to the bore b. Bore c is a few mils smaller than bore b to provide a stop for the pen shank 7 and to provide an annular ink space of about .010 thickness around a thin walled stainless steel tube S which is anchored in the bore d. The tube 8 is provided with a plurality of holes 9, four being shown, for the purpose to be described. The tube 8 extends from the bottom of the bore d to within about 1/16 of the pen nibs tip where it terminates in a pointed open end 10.

Co-axially within the bores a, b, c, and d and in bore f is fitted, inktight, an air and ink tube 11 made of thin wall stainless steel. This tube 11 extends from just within the inner end of the barrel at a point 12 to and just within the oval shaped open end of the larger tube 8.

Adapted to fit over the pen end of the hood which is oval in shape, is a cap 13 that preferably extends over a part of the barrel that fits onto the hood, 1. A holding clip 14 is fastened to the end of the cap 13 in any satisfactory manner as by welding. At the bottom of the cap is cemented a seal 15 of foam rubber or equivalent which is engaged by the pen nibs when the cap is put into position as shown thereby preventing any leaking of the pen.

Coming now to the operation of the pen and assuming the pen to be empty, it is lled by submerging the point end in an ink supply and then squeezing the barrel 5.

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This compresses the air in the barrel 5 forcing it down and out of the pen end of the axial air and ink tube 11. The barrel squeezing is then relaxed whereupon it resumes its normal cylindrical shape of larger volumetric capacity and reduced pressure, and atmospheric pressure forces ink from the ink reservoir up through the air and ink tube, whence it ows down into ther chamber or reservoir 4. This cycle of barrel squeeze and release operations is repeated a number of times until the barrel is iillled up to near the top end 12 of the air and ink tube 1 The pen is then turned point up or at least so that the top end 12 of the air and ink tube 11 is submerged in the reservoir ink, and with the oval-shaped hood opening upward. The barrel 5 is again squeezed which forces ink from the reservoir 4 up through the axial air and ink tube 11 to and out of its open end 10, whence it flows downwardly into the annular ink space between tubes 11 and 8 and laterally outward through the holes 9 in tube S and thence upwardly into the intermediate annular ink space c. When this is lled it overflows into the outer annular ink space formed by bore a between the outside of the pen point and the inside of the hood. When these annular collector spaces are lled, as is easily observed through the transparent hood 1 and at its open end, the barrel squeezing is then relaxed and the ink in the air ink tube 11 will be drawn into the reservoir 4, leaving this tube clear for air-breathing action while the pen is in point-down writing position. Unintended squeezing of the barrel 5 in this position can only force air out of the reservoir 4. Likewise, warming of the reservoirs air content by the hand while writing can only force air out of the pen, since the ink level is below the top, open end of the axial air and ink tube 7. Furthermore changes of atmospheric air pressure cannot affect the supply of ink at the writing point of the pen.

Each of the three annular ink spaces within the hood 1 of the pen has a radial thickness which will yield a degree of capillarity which will cause it to sustain its contained column of ink without undue ooding of the writing point of the pen. This capillary attraction however, is not so high as to prevent satisfactory feeding of the ink in these annular spaces to the pen nibs by gravity and the capillary attraction of the slit between the pen nibs themselves.

The three annular ink spaces comprise an ink collector, which when squeezed full, as previously described, is suicient for two or three normal size pages of writing. When this collector supply has been written out, it may be refilled from the barrel reservoir as described.

To prevent undesired expulsion of ink when the pen is carried upright or horizontally, in which cases the open, inner, upper end of the air and ink tube is submerged in the reservoir ink, the cap 13 is provided with a tubular foam rubber 15 or other yieldable inktight enclosure for the otherwise open end of the hood. This cap 13 is pushed onto the pen, which is preferably held point down while capping or uncapping it, so that accidental squeezing of the barrel 5 may not force ink from tube 11 into the cap.

Furthermore, if the pen has been securely capped, say at sea level, and later uncapped at a considerably higher altitude of lower atmospheric pressure as in an airplane, uncapping in a point-down position will allow the higher pressure air within the barrel to escape freely. If uncapped in a point-up position under these circumstances, a little ink might be squirted out of the open end of the tube 11 into the cap 13 and elsewhere after the cap is removed.

The friction and suction action of the soft rubber sea1 ing device is also relied upon for holding the cap 13 on the pen and therefore no additional provision need neces sarily be used, such for example, as screw threads, radial expansion friction members in the cap, etc. The soft rubber, hood-sealing member 15 of course has no air vent, so that when the cap is pushed firmly onto the pen hood 1, it seals the reservoir and collector against any possible escape of ink, which might be caused by an increase in internal over external air pressure caused by temperature increase of the pen or external atmospheric pressure decrease.

Furthermore, the soft rubber sealing member 15 accommodates itself to the oval shaped, hood opening around the protruding pen point, so that little if any free air space remains there in which ink can collect for obnoxious outflow when the cap is removed.

The friction and suction action of the caps sealing member 15 are sufficient to hold the cap in place on the pen under all ordinary mechanical and internal air expansion displacing forces.

If increase in the ink capacity of the annular collector spaces within the hood is desired, to provide a greater writing lineage before refilling the collector is necessary, the radial thicknesses of one or more of these may be increased, and its capillarity restored to the correct value by use of a tubular or other wick member 16 in the enlarged space or spaces as shown in Figure 4.

Other types of valve sealing devices may of course also be used to prevent escape of ink when the pens air ink tubes inner end is submerged in the reservoir ink. Such structures as I have shown in my co-pending patent application Serial No. 211,716, filed February 16, 1951, and now abandoned, or modifications thereof are considered satisfactory, although I prefer the form of sealing device disclosed herein because its operation is automatically insured by the capping of the pen and because this form is very simple and inexpensive. The axial air and ink tube 11 is carried completely through the pen as shown for the following reasons:

When the barrel reservoir is completely empty it is necessary to displace sufiicient air from the barrel to draw the ink from a bottle up to the top of the barrel, to a height of about 41/2 to 5 inches, with sufficient vacuum to cause an overow of at least one half to one cc. for the first such pumping cycle. Thereafter the displaced air and the degree of vacuum become greater as the barrel 5 becomes progressively more filled with ink. The air and ink tube 11 must not have a large volumetric capacity in its bore since this would reduce the amount of ink available for overflow into the reservoir for the first pumping cycle. During the barrelsqueezing, first half of the subsequent pumping cycles, the ink remaining in the axial air-ink tube 11 is expelled before more air can be forced out of the barrel. So, for this reason also, the volumetric capacity of this tube must be small. For the same reasons the ink collector should preferably not be serially connected in the ink and air passage to the barrel reservoir 4. If the air and ink tube 11 were terminated at point 9, for example, instead of at the outer mouth of the coaxial, larger tube, the suction half of each pumping cycle, barrel squeezing relaxed, the collectors annular ink collection spaces would have to be filled before ink could fill the tube 11 and overflow into the barrel reservoir 4, at the end 12 which is closely adjacent an inturned conically shaped end 17 of the barrel 5. By having this conically shaped surface, the air and ink are better guided to and from the tube 11.

Furthermore, during the barrel-squeezing first half of subsequent pumping cycles, all of the ink in these collector spaces would have to be forced out before additional air could be forced out of the barrel. The volumetric capacity of the collector spaces would therefore be added to that of the tube 11 in the air expelling and ink suction, filling operations, so that undue and possibly fracturing squeezing of the barrel would be neces.- sary for the first few pumping operations.

y above the ink in the collector.

As shown, therefore, my axial tube 11 passes completely through the ink collector, so that the collector is not included serially in this air expelling and ink inow path to the reservoir.

In filling the collector from the reservoir, by squeezing the barrel with the point end up, the ink is forced up and out of the outer, open end of the tube 11 and thence flows downward by gravity action, into the annular space between tubes 11 and 8 and thence, as previously explained, laterally through holes 9 in the tube 8 and outwardly into the intermediate co-axial, annular space c, from which it displaces its contained air as the ink level rises. When this is filled, it overflows into the outer, co-axial, annular space a around the pen point shank 7 until this space also is filled. In writing all three co-axial, annular ink spaces connect directly to the pen point and each one has sufficient capillarity to sustain its own column of ink, either directly, or with the aid of wick-like or other capillary material or construction.

Briefly stated, in the above description, the different spaces forming the collector are filled in series from the chamber 4 and when the pen is writing, the spaces are all in parallel to the pen point.

If the inner annular ink space between the tubes 8 and 11 includes for example, a tubular wick 16 as shown in Figure 4 and having a considerably greater resistance to air and ink ow than the bore of the tube 11, from a point where the holes 9 are now located outwardly to its open-atmosphere end, then a lateral hole through the wall of the tube 11 at said point will permit this inner axial tube 11 to act as an air breather tube for all of the annular ink collector spaces, so that air may flow upward through this tube to displace ink as it is written out of them, and further to prevent any air pressure increase Since tube 11 thus has a much lower air resistance for outgoing air, then the path through the wick-filled space c, in the reservoir-filling operation, little or no ink will be forced into or out of the collector spaces in filling the pen.

From the foregoing it will be seen, that I have made a pen that will accomplish the objects set forth in an irnproved manner.

Having thus described my invention, what I claim is:

1. A fountain pen having a hood with an ink con taining barrel, preferably having some flexibility, attached thereto, the hood carrying a pen point per se and also having fine bores of different diameters arranged in tandem alignment in the order of the diameter of the bores, with the widest bore outermost, the pen point having a split tubular shank extending through the largest or number 1 bore into the next smaller or number 2 bore and having a close fit therein and being spaced from the wall of the number l bore to define an ink collector space, a tube having an open end at a point between the pen nibs and passing all the way thru the third bore, this bore being large enough to leave an ink space around the tube, said tube terminating in the fourth bore adjacent to the fifth bore of smallest diameter, an air and ink tube fitting tightly in the fifth bore of the smallest diameter and extending from a point near the inner free end of the barrel through all the other bores to a point near the nib end of the pen point.

2. A fountain pen as defined in claim 1 further char- H acterized in that the first mentioned tube is preferably of stainless steel and has a plurality of transverse holes through its wall near the inner end of the third largest bore.

3. A fountain pen as defined in claim l further characterized in that the free end of the barrel has an inturned part over the free end of the air and ink tube for the purpose described.

4. A fountain pen as defined in claim 1 further characterized in that the extreme inner end of the hood is cup shaped with the inner end of the barrel fitting over the cup end and engaging the hood beyond the bottom of the cup and being flush with the surface of the hood beyond the said engaged part.

5. A fountain pen as defined in claim 1 further characterized in that the barrel is transparent and transversely compressible but longitudinally stiff with its free end having an inturned conically shaped part directly over and close to the end of the air and ink tube for the purpose described.

6. A fountain pen as set forth in claim 1 further dened in that the air and ink tube is of small internal diameter and extends from a point quite near the inner end surface of the free end of the barrel directly to the pen point per se while the spaces dened form a plural chambered ink collector having its chambers serially arranged with said air and ink tube during lling the collector but in parallel when the pen is writing.

7. A fountain pen as Set forth in claim 1 further defined in that the ink spaces around the air and ink tube are of different lengths within the hood and connected directly to the pen point per se, each space having suicient capillarity to sustain its own column of ink.

8. A fountain pen having a hood with an ink containing barrel directly attached to the hood at one end thereof, the barrel being `transversely compressible but substantially rigid longitudinally, the hood having at its free end a bore to receive directly the shank of a pen point, with a shorter bore of larger diameter outside the pen shank, the hood also having a bore of smaller diameter than said first bore positioned at the hood end that is engaged by the barrel, an auxiliary tube having its inner end fixed in this said smaller diameter bore and extending to a point within the pen nibs, an air and ink tube of relatively small volumetric capacity passing through the inner end of said hood and into said auxiliary tube and along the axis of said barrel to a point near the inner part of the free end of the barrel, the air and ink tube extending through said rst mentioned auxiliary tube to a point adjacent the pen nibs, the hood having a free bore through which said auxiliary tube passes and of a diameter suicient to carry considerable ink, the said auxiliary tube having transverse holes therein near the bottom of the free bore around it for the purpose described.

References Cited in the file of this patent UNITED STATES PATENTS 467,785 Walke Jan. 26, 1892 538,481 Cooley Apr. 30, 1895 549,165 Stewart Nov. 5, 1895 610,818 Means Sept. 13, 1898 1,523,904 Sato Jan. 20, 1925 2,419,483 Cloutier Apr. 22, 1947 2,522,553 Wittnebert Sept. 19, 1950 2,581,739 Wing Jan. 8, 1952 FOREIGN PATENTS 21,631 Great Britain 1908 818,824 France June 28, 1937 

